/*
 * Copyright (c) 2013-2014, Judison Oliveira Gil Filho <judison@gmail.com>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package org.judison.mongodm;


public class Projection {

	private MObject proj = new MObject();

	public Projection() {}

	public Projection(String... fields) {
		add(fields);
	}

	/**
	 * Allows you to map an field or use expressions, works in aggregate pipeline only
	 */
	public Projection put(String name, Object value) {
		proj.put(name, value);
		return this;
	}

	public Projection add(String... fields) {
		for (String field: fields)
			if (field.charAt(0) == '-')
				proj.put(field.substring(1), -1);
			else if (field.charAt(0) == '+')
				proj.put(field.substring(1), +1);
			else
				proj.put(field, +1);
		return this;
	}

	public MObject toMObject() {
		return proj;
	}

	@Override
	public String toString() {
		return proj.toString();
	}

}
